The present invention relates to a recording medium such as DVD-RW and the like, and a system for recording and reproducing the recording medium, and more particularly to a recording medium having a logical data structure for erasing recorded information and for protecting recorded information.
As an erasable recording medium, the floppy disc, audio cartridge tape, video cartridge tape, and others are known. The case of the floppy disc has a movable lug for setting the floppy disc to a recording inhibiting state and to a recording enabling state. When the movable lug is shifted to a record unable position by a user, recording (writing) of new recording information by a reproducing device is inhibited, thereby protecting the recorded information. When the movable lug is shifted to a record enable position, recorded information is initialized, or new information can be overwritten, thereby erasing the recorded information.
In the audio cartridge and video cartridge, a projected piece is provided on an end of the cartridge case. When the piece is removed by the user, the overwriting of new information on the recorded information is inhibited, thereby protecting the recorded information. On the other hand, when the projected piece is remained, new information can be overwritten, thereby erasing the recorded information.
Meanwhile, a DVD-Video using optical technique has been developed as a reproduction-exclusive recording medium which is possible to provide audio information and video information each having high quality compared with the above described recording medium. In recent years, the DVD-Video and DVD-RW (rewritable) has been remarked. The DVD-RW has a large recording capacity and is erasable and rewritable, keeping the physical compatibility in the DVD family including the DVD-Video.
The DVD-RW is a recording medium capable of making various titles and variously editing compared with the floppy disc, audio cartridge tape and video cartridge tape.
Therefore, it is possible to protect and erase recorded information by soft processing, unlike the floppy disc and others where the protect and erasure are performed by mechanical process. Furthermore, there has desired that the DVD-RW having a logical data structure enabling various title editing by effectively utilizing the characteristic of the disc is developed, keeping the physical compatibility in the DVD family.